Automated tape library machines have been used to greatly increase the efficiency and ease at which large quantities of data, such as generated by a computer network, can be stored and accessed by external host systems. Such machines are well known in the art, and generally include a robotic unit that moves within a housing under control of a microprocessor to retrieve and load desired tape cartridges into a tape drive unit. Theses machines further include a customer access port (CAP) or door arranged to allow a user to insert and remove data storage cartridges into the automated tape library machine without taking the entire machine off-line.
The mechanical design of a CAP for any given tape library machine must satisfy a wide variety of design factors relating to particular functional, safety, aesthetic, economic, and reliability requirements. Of these design factors, safety is perhaps the most important. In other words, customer operation of a CAP must be safe at all times such that at no time can the operator be in danger of physical harm from the moving robotic mechanisms of the library. Known CAP arrangements typically provide an input slot for receiving a cartridge from the customer, and a mechanism that subsequently moves the inserted cartridge from the input slot into engagement with the robotic tape system. Other arrangements use a tape loading and unloading mechanism that rotates one or more inserted tape cartridges from a position in which the tapes face outwardly through an opening in the library housing, to a position in which the tapes face inwardly so as to be accessible by a transport/robotic mechanism. An example of such a rotary arrangement is provided in U.S. Pat. No. 4,779,151 to Lind et al.
However, known CAP arrangements that use mechanisms to transport a tape from a user accessible position to a robot accessible position typically suffer the drawback of requiring expensive and complicated mechanical arrangements in order to meet high speed tape loading/de-loading and reliability demands. Therefore, a need exists for a simple access port arrangement which is both reliable and does not compromise customer/user safety